Distributor



y 1929- E. A. BOHLMAN 1,721,727

DISTRIBUTOR Filed April 14. 1926 2 Sheets-Sheet l I frnesZfiEafiZman. 107 3 a 51 471 125 57.

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July 23, 1929. E. A. BOHLMVAN 1,721,721

DISTRIBUTOR Filed April 14. 1926 2 Sheets-Sheet 2 JUL/6 172017.ErfiFsTfiEUZzZmnn LEJ] fia. W A

fizz [2 g2 Patented July 23 1929;

* UNITED STATES 1,721,727 PATENT OFFICE.

ERNEST A. BOHLMAN, CHICAGO, ILLINOIS, ASSIGNOR '10 KELLOGG SWITCHBOABDAND SUPPLY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

msrmau'ron.

Application filed April 14,

This invention relates todistributors such as are employed to supply thespark to the cylinders of a multi-cylinder internal combustion engineand particularly to a device of this character which is adaptedautomatically to advance or retard the spark asthe speed of the engineincreases or decreases.

Devices of this character have been constructed so that, as the speed ofthe engine is increased, the spark is automatically advanced and as thespeed of the engine decreases the spark is retarded. It has beendemonstrated that the best results are not ob-' tained when the advanceof the spark is in direct ratio to the speed. That is, with engines ofcertain types, it is desirable that the ratio of the spark advance tothe increase in speed of the motor be much greater within certain rangesof speed change than in others. With a large number of different ty esof motors, the best results are obtained y the provision of meanswhereby the spark ad vance is less for the higher rates of engine speeduntil a point is reachedwhen little, if any, further advance of thespark is de- "sirable.

In devices heretofore provided this variable ratio of the spark advancehas been obtained by providing a plurality of springs of differenttensions which come into operation successively, by providing camcontacts whereby the effective length of the lever. arm of thecentrifugal weight retracting means is changed or by like expedients.

The object of the present invention isthe provision of animproved deviceof the above described character whereby the variable ratio of sparkadvance, above referred to, is obtained by mechanism including a singleretractile (preferably spiral) spring which will be durable inconstruction, reliable in operation, yet, simple and cheap tomanufacture.

One of the features of the present invention resides in the arrangementwhereby the retractilespring for the centrifugal weight has a two pointengagement with the weight, one of which is effective at all times, theother becoming effective only after the weight has become displaced fromnormal. 7

Another feature closely related to the one just referred to is theconstruction whicli acts to displace the points of attachment at theends ofthe s'pringeach from the other as the weight moves outwardly.Other features and advantages will appear;

1926. Serial No. 101,856.

from time to time as the description of the invention progresses.

It is believed that the invention will be understood most readily from adetailed descrip-.

located showing the centrifugal weights or levers in fully retractedposition;

Fig. 4 is a view similar to Fig. 3 but showing the centrifugal weightsmoved outwardly slightly from normal;

Fig. 5 is a view showing the centrifugal weights moved substantially totheir outermost position;

Fig. 6 is a view similar to Fig. 3 but showing parts of the weightsbroken away to more clearly disclose the apparatus thereunder; an

Fig. 7 is a vertical sectional view through the centrifugal apparatuswhich forms the subject of the present invention.

Referring now to the drawings, in which like reference charactersindicate the same parts in the different views, 10 indicates a shaftwhich is connected to the motor and driven therefrom in such a manner asto rotate the interrupter cams and brush of the distributor at theproper rate of speed to supply spark to the cylinders at the propertimes. Secured to the shaft 10 by means of a pin (not shown) retained inposition by the coil spring 11 is a sleeve or collar 12. The shaft 10above the collar 12 passes through a bearing member 13 carried by thecup-shaped housing 14 within which the centrifugal spark advancingmechanism is arranged. The shaft'10 at the upper end thereof is providedwith a flange or enlargement 15 which rests upon the upper end of thebearing member 13.

Rigidly secured to the shaft 10 above the flange 15 in any desiredmanner is an irregularly shaped plate 16 (see Figs. 2 and 7) upon whichthe movable parts of the centrifugal devices are mounted. The upperend'of the shaft 10 is recessed, as indicated at 17, to remeans ofscrews, as 20,- is a plate or diaphragm ceive the end of the secondaryor distributor head shaft 18. Shaft 18 is provided with a flange 19which overlies the end of shaft 10 and the central portion of plate 16'.

Secured transversely of the housing 14 by 21 provided with a recess oroffset portion 22 at the center thereof within which rests the ballbearings 23 through which the reduced portion 24 of secondary shaft 18passes. Se-.

cured to the plate 21 above the bearings 23 is a second plate 25 whichacts to retain the bearing members 23 in position. Shaft 18 is providedwith a shoulder, as shown at 26,

which engages the lower side/of one of the bearing blocks of bearin 23and thus acts t prevent longitudinal displacement of th shaft 18 in anupward direction.

The upper end of the shaftv 18 is longitudinally slotted and is providedwith a tapered bore terminating in a threaded portion adapt? ed toreceive the screw 27 having a tapered head 28. Positioned about theupper end of the shaft 18 is the time cam 29, integral Aivith whichisthe mounting head 30 for the distributor block 31 formed of insulatingmaterial. The screw 27 with its tapered head'28 is adapted, when turneddown. to expand the the upper slotted end of the shaft 18 and firm- 1yretain the distributor cam 29 in position on the shaft. 9

Mounted on the plate 25 is the substantially annular member 32 formed ofinsulating ma terial and upon the insulating member 32 is a metalicmember. 33 (see Fig. 1), members 32 and 33 being securedto the'plate ordiaphram 21 by means of the screws 34, or in any other desired manner."Carried by the insulating plate 32 and insulated from the frame are thepivot pins 35 upon which the movable arms 36 of the lnterruptermechanism are mounted. Each of the arms 36 is provided with a contact 37adapted to engage a contact carried by a pin or screw 39 adjustablymounted in .the. bracket 40. The contact member 39 is adapted to beretained in adjusted position by any desired means, as for instance thelock nut 41. V

Overlying the upper end of the housing 14 is a cap or cover'42formed ofinsulating materlal within'which is moulded a high tension terminal 43and the distributor terminals 44 which are designed to be connected,respectively, to the-spark plugs of the motor. The

cap 42 is retained in position by means of the springs 45, the upperrebent ends 46 of which engage over the flanges 47 of the cover 42.

- Fixed to the high tension terminal 43 is a contact 48 arranged to beengaged. by the inner end of the spring contact member 49 carried by thedistributor block 31. In electrical engagement with the spring arm 49isthe distributor contact 50 adapted to be broughtsu'ccessivelyimmediately adjacent to the individual distributor contacts 44. It is tobe understood that the distributor contact 50 will be opposite therespective contacts 44 at the time the primary circuitofthe ignition Lapparatus is interrupted at contacts 37 by cups 56 are provided tosupply oil to the shaft or other moving parts of the distributor.Extending laterally from one side of thehousing 14 is an arm or plate 57adapted to be moved forward or backward in a rotary direction in orderto manually advance or retard the spark, it'being understood that thelower end of the bearing member 13 (shown in Fig. '2) is rotatablysupported fromthe inotor. As

the distributor head herein shown forms no briefly described. 1

The automatic" spark controlling mecha nism forming the subject ofthe-present inpart of the present inventionit has been only vention willnow be explained. -As above set. forth the plate 16,is fixed to the endof shaft 10 and the lower end of shaft 18 projects into the recessformed in the upper end of shaft 10. Resting on the flange 19 of .shaft18 and secured thereto in any desired manner, as by the nut 58, is aplate 59, the contour of which is shown in dotted lines .inFigs. 3 to 6.At

60 are indicated the centrifugal weights each of which consists of fiveplates or laminations 61, .62, 63, 64 and 65. Fixed to the plate 16,carried by shaft 10 at diametrically opposite sides are the pivot pins66 which pass through aligned openmgs in the layers or laminations 62,64 and65, the lamination 65 being offset to retain the lever or weightin spaced relation to the plate 16 as clearly indicated in Fig. 7.

The movement of, the weight vertically on the pin 66 is preventedby'means of the split. washer 67 which fits'into an: annular groove (notshown) in the pin 66.

- Each plate 64 is provided with an end 70 which extends beyond thepivot pin 66 and has therein a curved slot 71 which receives the end ofa pin 72 fixed to the, outer end of the plate 59. The slot 71 is so,formed that as the weight 60 moves outwardly the pin 7 2 is operated torotate the plate 59, and, therefore,

shaft 18 in a clockwise direction inrelation to plate 16, as viewed inFigs. 3, 4, 5 and 6 of the drawing's.- This movement iscl'early'a'pparent from a comparison of-Figs. 5 and 6. The, plates 61 to65, inclusive, are held together .by the rivets 73an'd 74, the latter ofwhich projects beyond "the laminations to form a point of attachment forone end of the spiral spring 75. This pin 74 also operates to limit theoutward movement of the centrifugal weights by engaging the lugs 76formed integrally with plate 16. Fixed to the plate 16 at the oppositesides thereof is a pair of pivot pins 77, upon each of which ispivotally supported one end of a spring attachment arm member 78provided with a finger 79 adapted to be engaged by a pin 80 projectingdownwardly from the lowermost lamination of the weight 60. Extendingdownwardly from arm 78 is a perforated lug.

or ear 81 to which is secured the opposite enrol of the spring 7 5. Itis to be understood, of course, that each of the weights 60 and partsassociated therewith are exactly identical.

Referring now to Fig. 3, it will be noted that the springs act normallyto retain the levers 60 in their retracted positions with their innerends substantially in engagement with the shaft 18. As the shaft 10rotates the shaft 18 is also rotated due to the pin 72 en-- gaging withthe edges of the slot 71. As the engine picks up in speed the weights 60are moved outwardly by the centrifugal force restrained only by theaction of the springs 75 on the pins 7 4. When. however. the weights 60reach substantially the position shown in Fig. 4 the pins engage thefingers 79 integral with members 78 and the further outward movement ofthe weights is thus resisted at their outermost extremities as well asby the tension of springs 75 acting on pins 74. As the speed of theengine continues to increase each weight continues to move outwardly andin so doing rotates one of the levers or arms 78 about its pin 77 untilthe parts of the device assume substantially the positions indicated 'inFig. 5 when further outward movement is prevented by pins 72 engagingthe ends of slots 71 and by pins 7 4 engaging extensions 7 6 as abovedescribed.

It will now be noted that the points of attachment of the ends ofsprings 7 5 to the depending ears 81 carried by plates 78 have beenmoved well beyond the lines. respectively, joining pivot pins 77 to pins74 to which are attached the ends of the springs 75. Thus the latterpart of the outward movement of the weights 60 is materially resisted bythe fingers 79. The effect of the inward thrust of fingers 79 isparticularly effective due to the fact that it acts on the portions ofweights 60 which are remote from their pivot pins 66. Also, it will bereadily understood that resistance-offered by the fingers 79 increasesrapidly as the arms 78 are rotated about pivot pins 77 and the points ofattachment of springs 75 to ears 81 pass beyond the lines joining pins74 and 77. Thus, after the engine has reacheda certain speed, the ratioof spark advance to increase in engine speed is very greatly reduced.

o It is to be understood that the relative proweights either nearer orfarther from their normal positions. Also, this engagement may takeplace at different points on the weights as, for instance, nearer theirsupporting pivot pins 66. The engagement of the weights with the plates78 may occur nearer m farther from the pivot pins 77 on which the arms78 are mounted and a, retractile spring of a different character may beemployed. It is thus obvious that the device may be readily modified toprovide practically any varying ratios of spark advance desired. Thespark controlling mechanism, above shown, operates to permit therelatively rapid advance of the spark when the engine first speeds upand then more effectively resists the outward movement of thecentrifugal weights and consequently the advanceof the timing mechanismas the weights move outwardly due to the increase in the speed of theengine until a point is reached where further movement (if the levers,and consequently further advance of the spark, is prevented.

It will be noted that the, spark advancing I mechanism herein disclosedconsists of but a few strong and durable parts so interconnected as toreduce danger of damage or derangement to a minimum. It also will beseen that the varying ratio of spark advance is obtained by the use-of asingle simple spiral wire spring, thus,'not only reducing danger ofbreakage to the minimum, but also rendering manufacture and assemblyvery cheap. In view of the many modifications contemplated by theinvent'or,.the invention should be limited only by the scope of theappended claims.

Having thus described my invention, what I claim is new and desire tosecure by Letters Patent of the United States is:

1. In a spark distributor, a driven shaft, a second shaft, sparkdistributing mechanism carried by said second shaft, a pivotallysupported weighted lever carried by one of said shafts, a retractilespring having one end attached to said lever for normally maintainingsaid lever .in its innermost position, an arm pivotally supported fromsaid one of said shafts, the other end of said spring being secured tosaid arm, means causing interengagement of the outwardly moving portionof said lever with said 'arm as said lever moves outwardly impelledby-centrifugal force and means, including said lever,

interconnecting said shafts arranged to cause 2. In a spark distributor,a driven shaft,

a second shaft substantially in alignment with said driven shaft, sparkdistributing mechanism actuated by said second shaft, a weighted leverpivotally supported from one of said shafts, an arm pivotally supportedfrom said one of said shafts, a spiral spring for normally retainingsaid lever in its retracted position, one end of said spring beingjoined to said lever, the otherend being connected to said arm, aprojection on said arm in the path of movement of theoutwardly movingportion of said lever as said lever moves outwardly, and means includingsaid lever interconnecting said shafts and arranged to cause a rotarymovement of said second shaft relative to said driven shaft responsiveto the movement of said lever.

3. In a spark distributor, a driven shaft, a.

second shaft substantially in alignment therewith, spark distributingmechanism actuated by said second shaft, a plate carried by one of saidshafts at substantially right angles thereto, a weighted lever pivotallymounted on said plate, an arm pivotally supported on said plate, aspring for retaining said lever in retracted position, one epd of saidspring being joined to said lever and the other end to said arm, saidarm being positioned in the path of movement of the outwardly movingportion of said lever as said lever moves outwardly impelled bycentrifugal force and means, including said lever, interconnecting saidshafts arranged to cause a rotarymovementof said second shaft relativeto said driven shaft responsive to the movement of said lever.

4. In a spark distributor, a driven rotary device, a second. rotarydevice, spark distributing mechanism carried by said second device andarotarily adjustable connection between said devices comprising aweighted lever pivotally joined to the said'driven device, a retractilespring having one end attached to said lever, a movable gnember to whichthe other end of said spring is secured, means causing engagement ofthe'outwardly moving portion of said weight with said ;weighted leverpivotally joined to said plate a retractile spring having one endattached to said lever, a movable member carried by said'plate andlocated at the end of said plate Wardly impelled by the centrifugalforce produced by the rotary movement of said driven device and meansinterconnecting said lever and said second device arranged to cause arotary movement of said second device relative to said driven deviceresponsive to the movement of said lever.

6. In a spark distributor, a driven rotary device, a second rotarydevice, spark distributing mechanism actuated by said second device, aplate fixed to said driven device, a weighted lever pivotally joined tosaid plate, a retractile spring having one end attached to said lever, apivotally supported arm located on the end of said plate opposite tothat at which ,the lever is pivotally supported but adjacent theweighted portion of said lever, the other end of said spring beingsecured to said pivotally supported arm, means-causing engagement ofsaid lever with said arm as said lever moves outwardly impelled by thecentrifugal force produced by the rotary movement of said driven device,a plate fixed to said second device, and means secured to said platefixed to said second device for interconnecting said lever and saidsecond device arranged to cause a rotary movement of said second devicerelativeto said driven device responsive to the movement of said lever.

7. In a spark distributor, a driven shaft, 7

a second shaft, spark distributing mechanism actuated by said secondshaft, a weighted lever pivotally supported from said drlven shaft, aretractile spring having one end attached to said lever for normallymaintaining said lever in its innermost position, a plate pivotallysupported from said driven shaft, the other end of said spring beingjoined to said plate, means causing interengagement of the outwardlymoving portion ofsaid lever with said plate as said lever movesoutwardly impelled by centrifugal'forceproduced by rotary movement ofsaid driven shaft and a plate fixed to said second shaft and aprojecting stud secured thereto for interconnecting said lever and saidsecond shaft arranged to cause a rotary movement of said second shaftrelative to said driven shaft responsive to the movement of said lever.v

8. In a spark distributor, a driven shaft, a second shaft, sparkdistributing mechanism carried by saidsecond shaft, a plate fixed tosaid driven shaft, a weighted lever pivotally supported from said plate,a retractile spring having one end attached to said lever for normallymaintaining said lever in its innermost position, an arm pivotallysupported from which the weighted lever is pivotally supported on saidplate, the other end of saidspring being secured to said arm, a depend-wmg member fixed to said lever causing interengagement of said lever withsaid arm as said lever moves outwardl impe1led by the centrifugal forceproduce by rotarymovement of said drivenshaft and means interconnectingsaid lever and said second shaft arran ed to cause a rotary movement ofsaid secon shaft relative to said driven shaft responsive to themovement of said lever.

' 9. In a s ark distributor, a driven shaft, a second sha substantiallyin alignment with said driven shaft spark distributing mechanismactuated by said second shaft, a weighted lever pivotally supported fromsaid driven shaft, an arm pivotally sufpported from said driven shaft a'spring or normally retaining said lever in its retracted position, oneend of said spr' being joined to said lever, the other end bemgconnected to said arm, a projection on said arm. in the path of movementof the outwardly moving portion of said lever adapted to engage saidportion as said lever moves outwardly, and

t means interconnecting said lever and said second shaft arranged tocause a rotary so said driven shaft responsive to the movement of saidlever. .1

10.. In a spark distributor; a driven shaft, a second shaftsubstantially in alignment with saiddriven shaft, said driven shaftnavmg a! longtudinal' bore in the end thereof receiving e end of saidsecond shaft,

distributing mechanism actuated by sai second shaft, a late supported b'said driven shaft, a we ted lever pivota ly., supported from said p ate,an armpivotally supported from said plate at the o posite end'at whichthelever is supported ut adjacent to the weighted portion of said lever,a' spiral spring for normally retaining said lever in w I itsretractedposition one end of said sp being joined to lever, the other diid beingto said ,arm,'said arm bein 1n the path of movement of sai tlever assaid lever moves outwardly, and

movement of said second shaft relative "to.

ark

means interconnecting said lever and said second shaft arranged to causea rota movement of said second shaft relative to said driven shaftresponsive to the movement of said lever.

11. In a spark distributor a driven shaft, a second shaft substantiallyin alignment therewith, spark distributing mechanism actuated by saidsecond shaft, a plate carried by said dnvera shaftat substantially ri htangles thereto, a weighted lever pivota y mounted on one end of saidplate, an arm pivotally supported on the opposite end of said plate anadjacent the weighted portion of said lever, a spring for retainmg saidlever in retracted position, one end of said spr' beingjoined to saidlever and the other end to said arm, said arm bein 1 positioned in thepath of movement of sai lever as said lever moves outwardly impelled bycentrifugal force and means interconnecting said lever and said secondshaft arrange to cause a rotary movement of said second shaft relativeto said driven shaft responsive to the movement of said lever. I

12. In a spark distributor, a driven shaft, I a second. shaftsubstantially in alignment therewith, said driven shaft having a lontudinal bore in the end thereof receiving e vend of said second shaft,spark distributing mechanism actuated by said second shaft, a platecarried by said driven'shaft at substantially right angles thereto, aweighted lever pivotally mounted onone end of said'plate,

arm Eivotall su ported on said plate ad jacent t e. weig te portion ofsaid lever, a spiral s' ring for retaining. said lever in retractedposition, one end of said spring being 'oined to said lever and theother en to sal arm, said am being positioned in thepath of movement ofsaid lever as said lever moves outwardly impelled by centrifugal forceand means interconnect' said, lever and said second shaft -arran tocause a rotary movement of said second shaft rela- 95 tive to said driveshaft responsive to the 1 movement of said ever. v I have signed thisony whereof specification. p ERNEST A. BOHLMAN.

